Common dimensions of toothbrushes have evolved from designers' experiences and from users' feedback during many generations. Toothbrushes having common dimensions are comfortable for brushing teeth of adults and children. A toothbrush having common dimensions fits easily and comfortably along the gums and under the tongue of the user, and it is efficient in brushing several teeth at the time. These dimensions constitute a mature subject matter wherein improvements are now rare. Therefore, it is believed that any innovation in toothbrushes should respect the importance of maintaining these common dimensions.
Water jets have also been proven to be efficient in rinsing one's teeth and mouth. Several attempts have been made in the past to incorporate a water conduit and a nozzle in a toothbrush, but generally this has been done to the detriment of maintaining ideal toothbrush dimensions.
It is believed that the toothbrushes of the prior art having a water jet incorporated therein are difficult to introduce in the mouth; they cannot be brought close to the gum line for treating the gums for example, and they are unstable inside the mouth of the user. These inconveniences will be better appreciated when understanding the structural differences in the dental treatment instrument described herein.
Examples of toothbrush and water jet combinations of the prior art are numerous and include the devices described in the following documents:    U.S. Pat. No. 913,184 issued to C. L. Alexander on Feb. 23, 1909;    U.S. Pat. No. 1,408,520 issued to O. H. Larsen on Mar. 7, 1922;    U.S. Pat. No. 1,580,799 issued to R. Anzalone on Apr. 13, 1926;    U.S. Pat. No. 3,214,775 issued to I. I. Murov et al., on Nov. 2, 1965;    U.S. Pat. No. 3,273,189 issued to L. E. Levinson et al., on Sep. 20, 1966;    U.S. Pat. No. 3,509,874 issued to T. Stillman on May 5, 1970;    U.S. Pat. No. 3,593,707 issued to G. W. Pifer on Jul. 20, 1971;    U.S. Pat. No. 4,175,879 issued to P. Molinari on Nov. 27, 1979;    U.S. Pat. No. 4,303,064 issued to M. J. Buffa on Dec. 1, 1981;    U.S. Pat. No. 4,743,199 issued to A. Weber et al., on May 10, 1988;    U.S. Pat. No. 4,928,675 issued to T. F. Thornton on May 29, 1990;    U.S. Pat. No. 5,304,010 issued to C. Hsing-San on Apr. 19, 1994;    U.S. Pat. No. 5,746,595 issued to F. E. Ford on May 5, 1998;    U.S. Pat. No. 5,876,135 issued to Y. J. Wang et al., on Mar. 2, 1999;    US Patent Appl. 2004/0045107 filed by Z. Egeresi on Mar. 11, 2004;
The documents of the prior art that are listed above generally disclose toothbrushes having water jets pointing amongst the bristles of the toothbrush; toward the far end of the bristle pad, or at right angle backward relative to the bristle pad. It is believed that these arrangements are inconvenient for holding the nozzle of the water jets close to a dental region to be irrigated for example.
The water jets that are of interest herein pertain to dental and mouth treatment. These jets can be used to clean gaps between the teeth as an alternative to flossing for example, or to massage the gums. Also, the water pumped through these jets may contain a solution such as mouthwash, fluoride, baking soda, salt, a healing product, or other solutions recommended by dentists to reduce plaque; to disinfect the gums; or to alleviate the pain of a toothache.
During these treatments, it is important to be able to hold the water spray steady pointing against a specific region in the mouth of the user. The efficiency of these treatments depends on the stability and precision with which the user can hold the water spray pointing at the region to be treated. In that respect, dislodging food particles from between the teeth is good image to appreciate such requirement of stability and precision in treating one's teeth.
The prior art also contains dental irrigation instruments that are used to maintain dental hygiene basically. Examples of these instruments are described in the following documents:    U.S. Pat. No. 3,386,439 issued to T. P. Harper on Jun. 4, 1968;    U.S. Pat. No. 3,499,440 issued to A. Gibbs on Mar. 10, 1970;    U.S. Pat. No. 3,973,558 issued to R. D. Stouffer et al., on Aug. 10, 1976;    U.S. Pat. No. 4,672,953 issued to E. E. DiVito on Jun. 16, 1987;    U.S. Pat. No. 4,941,459 issued to S. K. Mathur on Jul. 17, 1990;    U.S. Pat. No. 5,231,978 issued to T. Kao et al., on Aug. 3, 1993.
These spray nozzles are held in one's hand with the tip inserted in the mouth. The precision of these water jets depends on how steady one can hold the nozzle in his/her hand, while standing in front of a mirror for example. It is believe that these instruments are better used by a second person such as a dentist for example, who can rest his/her hand on the patient's chin, while steadying the patient's head with the other hand. This image illustrates the difficulties in using water jet instruments and it will be better understood if one can visualize that the user of the instrument could be a child or a person having less dexterity than others.
Therefore it is believed that there is a market need for a toothbrush and water jet combination which is easy to hold steady in one's mouth, and which is movable with precision in one's mouth.